Method and means for training operators of sound locating devices



June 30, 1931. H. B. ELY 1,811,997

i METHOD AND MEANS FOR TRAINING OPERATORS'OF SOUND LOCATING DEVICES Filed Dec. 4, 1928 2 Sheets-Sheet l June 30, 1931. H. B. ELY 1,811,997

l METHOD AND MANS FOR TRAINING- OPERATORS OF SOUNDLOCATING DEVICES" Fled Dec. 4, 1928 2 Sheets-Sheet 2 /a f7 x28 gmc/nto@ -Hram E ElyKL a@ MM @WK Patented June 30, 1931 PATENT OFFICE UNITED STATES HIRAM B. ELY, OF PHILADELPHIA, PENNSYLVANIA IETHOD AND MEANS FOR TRAINING OPERATORS OF SOND LOCATING DEVICES.

application med December 4, 192s. serial Np. 323,741.

(GRANTED UNDER THE ACT F MARCH 3, 1883, AS AMENDED APRIL 30,1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a method of and `means for training operators of sound locating devices which are of the type function- -ing according to the system of binaural comparison.

lo VThe purpose of the invention is to provide a. self-contained unit, including a source of sound, means under the control of an instructor for varying the length of travel of the sound to the ears of the` listener to establish a phase difference and means, including an 4indicating device, under't-he control o'thelistener for counter-acting the displacement imparted `by the instructor to equalize the length of travel of the sound.

n With the foregoing and other objects in view, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, itbeing understood that g changes in the precise embodiment of the invention herein disclosed may be made 'within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is 3 illustrated in the accompanying drawings,

wherein:

Fi 1 is aschematic view illustrating the principle of the invention;

Fig. 2 is a view in side elevation of an apparatus constructed in accordance with the invention;

Fig. 3 is a plan view thereof;

Fig. 4 is a view in side elevation of the assembled unit with an external source of sound.

Referring to the drawings by numerals of reference:

In Fig. 1 a sound wave emanating from a sound producing device 4 of any suitable character is conducted through a receiver 5 to a tube 6 which is divided to form paths of communication 7--7 leading to ear pieces 8 8. Each of the paths of communication includes an adjustable element 9 whereby the i9 length of the paths may be varied. The adall wired in the customary manner.

The instructor by varying the distance of sound transmission from the receiver to the ear of the listener creates an impression of lateral direction which the listener can convert into a central or balanced direction vby imparting to the differential a displacement complementary to that imparted by the instructor, thereby 'equalizing the distance 'and the time oftravel of the sound to his ears.

When the paths of communication 7 are balanced, a pointer 16 on one of the adjustable elementsv 9 will register with the zero of a scale 17. Failure on the part of the listencrto correctly balance the paths 7 will be indicated on the scale and such indications will-serve as a measure to determine the fitness and aptitude of the listener orto determine the percentage error which must be, applied to the readings when he is operating ai sound locating device; If the instructor and the listener act on the differential in unison, the annulus 11 and the adjustable elements 9 will remain stationary. v

Referring to Figs. 2 and 3 which illustrate an actual embodiment of the invention, there is provided a container 18 in which is mounted the sound-producing unit 4 inthe form of a standard vacuum tube oscillator com,

prising batteries 19, transformer 20, condenser 21, rheostat 22 and vacuum tube 23 The paths of communications 7 are in the form of U shaped tubes carried by a block 24 and have slidable bent portions which constitute the adjustable elements 9. The tubes 7 are branched from the tube 6 which carries the receiver 5. The differential gear 12 is p ositioncd adjacent the block 24 and is mounted through its axles 25 by gear speed reduction and 28, the hand wheel 27 of the shaft 15 being preferably of the same size as the hand Wheel on the'sound locating instrument forV which the listener is to be trained. The annulus 11 of the differential gear mechanism isi equipped with brackets 29 for attachment j of the rods 10.

In Fig. 4 there is indicated va sound source consisting of. a phonograph record` 30 which, in order to add realism to the training, reproduces the sound of an aeroplane in fiight,

rI claim: y

1, The method of training in binaural comparison which consists in establishing a source of sound from a fixed position transmitting the sound through a single receiver and thence by separate paths to eachear of a listener, arbitrarily varying said paths to create an impression of lateral direction, having the listener equalize the paths to perceive an impression of central direction and measuring any failure to equalize the paths.

V2. The method of-training in binaural comparison which vconsists Y in establishing a source of sound, transmitting the sound through a single receiver and thence by separate paths to each ear of ailistener, arbi-y trarily varying said paths to create an impression `oflateral direction, having the ,listener equalize the paths to perceive an impression of cent-ral direction and measuring any failure to equalize the paths.

3. The method of training in binaural comparison which consists in establishing av ysound 'from the receiver to each earv of the listener and a dual control operating mechanism for adjusting the sound conducting means. y Y Y 8. Means for training a listener in binaural comparison including vseparate adjustable means for conducting sound to each ear of the listener and a dual control operating mechanism for adjusting the sound `conducting means.

9. Means for t-raining in binaural compari-V A son comprising a sound source, tWo paths of i sound transmission, means for supplying a movement Which Willvarythe length of the paths of transmission and an additional means for supplying a movement which will vary the length of the ypaths of transmission whereby the first ymovement may be counteracted. i

10. A method of binaural comparison em-` bodying, establishing a unitary source of sound 1 Wave, propagation, conducting said Waves separate paths, and varying the length o the paths at will to change the sense of direction :of said source of sound Wave,

propagation.

HIRAM B. ELY.`

.4. Means for training a listener in binaural l' comparison, including a container, a source of sound inthe container, va single sound'receiver, separate adjustable means for conducting the sound from the receiver to each ear of the listener, a differential gear connected With the adjustable conducting means, a'dual control for theV differential gear and means for indicating the relative positions of the conducting means.

5. VMeans for training a listener in-bina-ural comparison, including 'a single soundreceiver, separate adjustable means for conducting the sound from the receiver to each ear of the listener, la differential gear connect-ed with the adjustableconducting means, a dual control for the differential gear and .means for indicating the relative n positions of the conducting means. 

